1. Technical Field
The present invention relates to a data processing circuit, a physical quantity detection circuit, a physical quantity detection device, an electronic apparatus, and a moving object.
2. Related Art
At present, physical quantity detection devices capable of detecting various physical quantities, such as acceleration sensors detecting acceleration and gyro sensors detecting angular velocities, are widely used for various systems or electronic apparatuses. Physical quantity detection devices in which A/D conversion circuits convert physical quantity detection signals (analog signals) into digital signals and output detection information as digital data can output digital signal with high noise resistance. Therefore, systems that include the physical quantity detection devices and MCUs receiving digital data and performing calculation can ensure high reliability.
In the systems, when the MCUs do not synchronize frequencies for sampling the digital data with sampling frequencies of A/D conversion circuits included in the physical quantity detection devices, there is a problem that folding noise of signals occurs by reception (sampling) of the MCUs. JP-A-2006-345508 discloses a frequency conversion method of initializing a circuit from a sampling rate ratio of an input to an output and performing optimum over/under sampling and filter processing.
However, in the frequency conversion method disclosed in JP-A-2006-345508, it is necessary to know the sampling rate ratio. Therefore, when the sampling rate ratio can be comprehended in advance, the frequency conversion method is effective. However, in an event in which the MCU acquires data at an irregular timing, it is difficult to comprehend an exact sampling rate ratio and the frequency conversion method is not necessarily an effective method.